scholarly journals Influence of some sol-gel synthesis parameters of mesoporous TiO2 on photocatalytic degradation of pollutants

2016 ◽  
Vol 22 (1) ◽  
pp. 65-73
Author(s):  
Aleksandar Golubovic ◽  
Ivana Veljkovic ◽  
Maja Scepanovic ◽  
Mirjana Grujic-Brojcin ◽  
Natasa Tomic ◽  
...  
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
Textile Dye ◽  
Reactive Orange 16 ◽  
Higher Temperature ◽  
Tio2 Nanopowders ◽  
Gel Technique ◽  
Reactive Orange ◽  
Sol Gel Synthesis

The titanium dioxide (TiO2) nanopowders were produced by sol-gel technique from tetrabutyl titanate as a precursor by varying some parameters of the sol-gel synthesis like the temperature (500 and 550 ?C) and the duration of the calcination (1.5, 2, and 2.5 h). X-ray powder diffraction (XRPD) results have shown that all synthesized nanopowders are dominantly in anatase phase, with the presence of a small amount of rutile in samples calcined at 550 ?C. According to the results obtained by Williamson-Hall method, the anatase crystallite size was increased with the duration of the calcination (from 24 to 29 nm in samples calcined at lower, and from 30 to 35 nm in samples calcined at higher temperature). The analysis of the shift and linewidth of the most intensive anatase Eg Raman mode confirmed the XRPD results. The analysis of pore structure from nitrogen sorption experimental data described all samples as mesoporous, with mean pore diameters in the range of 5-8 nm. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the textile dye (C.I. Reactive Orange 16), carbofuran and phenol.

scholarly journals Synthesis of anatase nanopowders by sol-gel method and influence of temperatures of calcination to their photocatalitic properties

2015 ◽  
Vol 47 (1) ◽  
pp. 41-49 ◽  
Author(s):  
A. Golubovic ◽  
B. Simovic ◽  
M. Scepanovic ◽  
D. Mijin ◽  
A. Matkovic ◽  
...  
Keyword(s):  
Photocatalytic Performance ◽  
Anatase Phase ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
Textile Dye ◽  
Reactive Orange 16 ◽  
Tio2 Nanopowders ◽  
Gel Technique ◽  
Reactive Orange ◽  
Brookite Phase

The titanium dioxide (TiO2) nanopowders were produced by sol-gel technique from tetrabutyl titanate as a precursor, varying the temperature ?f calcination (from 500 to 550?C with the step of 10 ?C). XRPD results have shown that all synthesized nanopowders are dominantly in anatase phase. The analysis of the shift and linewidth of the most intensive anatase Eg Raman mode confirmed the XRPD results and added the presence of small amount of highly disordered brookite phase in all samples. The analysis of pore structure from nitrogen sorption experimental data described all samples as mesoporous, with mean pore diameters in the range of 1.5 and 4.5 nm. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the textile dye (C.I. Reactive Orange 16). The sample calcined at temperature of 510?C showed the best photocatalytic performance.

Sol-Gel Synthesis and Characterization of Neodymium-Ion Doped Nanostructured Titania Thin Films

2001 ◽  
Vol 703 ◽  
Author(s):  
Andrew Burns ◽  
W. Li ◽  
C. Baker ◽  
S.I. Shah
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Anatase Phase ◽  
Sol Gel ◽  
Ionic Radii ◽  
Si Substrates ◽  
Gel Technique ◽  
The Difference ◽  
Sol Gel Synthesis

ABSTRACTNd doped TiO2 nanostructured thin films were prepared by sol-gel technique on quartz and Si substrates using TiCl4 precursor. As-deposited amorphous films were annealed to form anatase phase in the thin films. The film grain size increased with annealing temperature. Above 800°C, rutile began to segregate and the grain size decreased slightly.The photodegradation of 2-chlorophenol (2-CP) was studied. Doping TiO2 with Nd+3 reduced the photodegradation time. The difference in the ionic radii of Nd+3 and Ti+4 and the oxygen affinities of Nd and Ti were responsible for this effect. These differences help promote electron trapping, thereby increasing the lifetime of the holes which are responsible for the oxidation of 2-CP.

Preparation and Photocatalytic Activity of TiO2/Opal Composite

2013 ◽  
Vol 668 ◽  
pp. 13-16
Author(s):  
Qing Shan Li ◽  
Biao Zhan ◽  
Wei Hong ◽  
Guang Zhong Xing
Keyword(s):  
Methylene Blue ◽  
Uv Light ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
Methylene Blue Solution ◽  
Photocatalytic Decolorization ◽  
Uv Light Irradiation ◽  
Photocatalytic Activities ◽  
Blue Solution ◽  
Gel Technique

Opal as a carrier, tetrabutyl titanate as a titanium source, TiO2 loaded on opal was prepared by sol-gel technique. The photocatalysts were characterized by XRD, TEM and UV-VIS absorption spectrum. Their photocatalytic activities were examined by the photocatalytic decolorization of methylene blue solution under UV light irradiation. The effects of calcination temperature, the amount of TiO2 loading and pH on photocatalytic activities were discussed. The results show that TiO2 supported on opal induced enhancement of photocatalytic decolorization rant and TiO2 doping is about 30 wt. % with 92.15% of decolorization rate at 700°C.

scholarly journals One pot transparent sol-gel synthesis of TiO2 nanospheres with pristine anatase phase and their physicochemical characteristics

2016 ◽  
Vol 2 (1) ◽  
pp. 23-30 ◽  
Author(s):  
O.S.N. Ghosh ◽  
◽  
S. Gayathri ◽  
D. Alagarasan ◽  
K.V.P. Kumar ◽  
...  
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Physicochemical Characteristics ◽  
One Pot ◽  
Sol Gel Synthesis

scholarly journals Calcination Effect on Structural Trasformation of Barium Titanite Ferroelectric Ceramic by Sol-Gel Method

2019 ◽  
Vol 9 (1) ◽  
pp. 5893-5896
Keyword(s):  
Glacial Acetic Acid ◽  
Sol Gel ◽  
Ferroelectric Ceramic ◽  
Tetrabutyl Titanate ◽  
Chemical Modifier ◽  
Barium Acetate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Scanning Electron

High purity barium titanate BaTiO3 was successfully synthesized by using the sol-gel technique. Barium acetate Ba(CH3COO)2 and tetrabutyl titanate, Ti(C4H9O)4 was dissolved moderately in the solvent of glacial acetic acid and ethanol was added as the chemical modifier. The synthesized BaTiO3 nanoparticle was calcined at the temperature range of 700 ºC to 1100 ºC. The powders were further characterized by X-ray diffraction and scanning electron microscopy (SEM). Fined BaTiO3 powders result indicates the phase of tetragonal structures and high crystallites of BaTiO3. It was observed that the crystallinity and particle size of BaTiO3 is greatly influenced by the calcination temperature.

Synthesis of Titania coated Alumina Particles by a Hybrid Sol-gel Method

2002 ◽  
Vol 740 ◽  
Author(s):  
A.D. Schmidt ◽  
S.B. Majumder ◽  
P.S. Dobal ◽  
R.S. Katiyar ◽  
D.C. Agrawal
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Microscopy Imaging ◽  
Nano Crystalline ◽  
Heat Treated ◽  
Alumina Particles ◽  
Gel Technique ◽  
Titania Coatings ◽  
Titania Coating

ABSTRACTModifying their surface with a coating of another ceramic material can dramatically alter the properties of ceramic particles. In the present work we have demonstrated that the Al2O3 particles can be successfully coated by TiO2 using a novel sol-gel technique. The nature of these coatings was predicted on the basis of scanning electron microscopy imaging in conjunction with the micro-Raman scattering measurements. The surface morphology of these particles shows that either individual or group of sub-micron alumina particles are coated with the nano-crystalline titania particles. The thickness of the titania coating could be varied by changing the precursor sol concentration. Amorphous titania was converted to anatase phase at 400°C and upon further heating it started transforming to rutile phase, and both these phases coexisted in the coated particles that were heat treated up to 800°C. The mechanical strength of the titania coating was measured qualitatively by ultrasonicating the coated powders for longer duration to observe that titania coatings are strongly adhered with the alumina particles.

scholarly journals Photocatalytic efficiency of titanium dioxide immobilized on PVP/AAc hydrogel membranes: A comparative study for safe disposal of wastewater of Remazol Red RB-133 textile dye

2005 ◽  
Vol 7 (4) ◽  
pp. 181-185 ◽  
Author(s):  
Hoda S. Hafez ◽  
A. El-Hag Ali ◽  
M. S. A. Abdel-Mottaleb
Keyword(s):  
Sol Gel ◽  
Textile Wastewater ◽  
Textile Dye ◽  
Photocatalytic Efficiency ◽  
Safe Disposal ◽  
Hydrogel Membranes ◽  
Different Types ◽  
Degussa P25 ◽  
Gel Technique ◽  
Remazol Red

The paper reports on the photocatalytic efficiency ofTiO2nanoparticles immobilized on polyvinyl pyrrolidone/acrylic acid (PVP/AAc) copolymer hydrogels, which are prepared by means ofγ-rays induced homo- and copolymerization. The efficiency of immobilized photocatalyst is tested on a commercial textile dye namely Remazol Red RB-133. The results are compared with photocatalytic efficiencies of different types of non supportedTiO2photocatalysts such as aqueous slurries of colloidalTiO2prepared by sol-gel technique, and commercially available Degussa P25. Although less efficient than nonsupported ones, the hydrogel supportedTiO2photocatalyst has the practical advantages of easy separation and removal from the reactors. This makes it a viable technique for the safe disposal of textile wastewater into the water streams.

Structural and Optical Characterization of Synthesized TiO2 Nanopowder Using Sol–Gel Technique

2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650002 ◽  
Author(s):  
S. Lourduraj ◽  
R. Victor Williams
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Visible Spectrum ◽  
Average Crystallite Size ◽  
Xrd Analysis ◽  
Force Microscopy ◽  
Morphological Studies ◽  
Atomic Force ◽  
Gel Technique

The nanocrystalline TiO2 powder was synthesized by sol–gel method. The XRD analysis reveals that TiO2 powder was highly crystalline (anatase phase) and nanostructured with tetragonal system. The average crystallite size after calcined at 673[Formula: see text]K is found to be 7.7[Formula: see text]nm. The surface morphological studies using scanning electron microscopy (SEM) exhibit that the formation of nanosized TiO2 particles with less densification nature. Atomic force microscopy (AFM) topography exhibits the uniform distribution of spherical-shaped particles. The energy dispersive X-ray spectroscopy (EDX) confirms the presence of Titanium and Oxygen in synthesized TiO2 nanopowder. The value of optical bandgap of TiO2 nanopowder calculated from UV-Visible spectrum is 3.45[Formula: see text]eV. The presence of TiO2 particles is confirmed from the dominant fourier transform infrared (FTIR) peaks at 621[Formula: see text]cm[Formula: see text] and 412[Formula: see text]cm[Formula: see text].

Phase transformation and characterization of TiO2 and ZrO2 addition in the Li2O–Al2O3-SiO2 gels

1996 ◽  
Vol 11 (10) ◽  
pp. 2611-2615 ◽  
Author(s):  
Ming-Hong Lin ◽  
Moo-Chin Wang
Keyword(s):  
Phase Transformation ◽  
Sol Gel ◽  
Peak Position ◽  
X Ray Diffraction ◽  
Transformation Behavior ◽  
Ceramic Powders ◽  
Higher Temperature ◽  
Gel Technique ◽  
Dta Curves

Glass-ceramic powders with a composition of Li2O · Al2O3 · 4SiO2 (LAS) have been synthesized by the sol-gel technique using LiOCH3, Al(OC2H5)3, Si(OC2H5)4, Ti(OC2H5)4, and Zr(OC2H5)4 as starting materials and the phase transformation behavior during calcination has been investigated. Differential thermal analysis (DTA), x-ray diffraction (XRD), and scanning electron microscopy (SEM) were utilized to determine the thermal behavior of the gels. Considering the LAS gels with 6.0 wt. % TiO2 and various wt. % ZrO2 content, and peak position of the β-spodumene phase formation in DTA curves was shifted to a higher temperature when the ZrO2 content was increased. The activation energy of β-spodumene crystallization was 283.8 kcal/mol for LAS gels with 6.0 wt. % TiO2 and 2.0 wt. % ZrO2. Unlike foregoing studies for LAS gels, during calcination of the dried LASTZ gels from 800 °C to 1200 °C neither β-eucryptite nor γ-spodumene was noted to be present. The crystallized phases comprised of β-spodumenes as the major phase and rutile (TiO2) together with zirconia (ZrO2) are precipitated as minor phases.

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